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NVIDIA nForce 680i LT SLI
Date: Mar 26, 2007
Author: Alex Evans
Introduction & Specifications

Nvidia had been somewhat slow getting out of the gate with their initial Intel Core 2 compatible chipsets. Their first nForce 4 and nForce 5 series products for the Core 2 weren't very well received by enthusiasts, who mostly opted for more stable and less power hungry Intel based chipsets, unless Nvidia's SLI technology was an explicit requirement. While it has taken them a bit longer than expected to get their footing for this new processor architecture, it seems like Nvidia is truly hitting their stride with the nForce 600 series of products.

Currently, Nvidia is producing three chipset products in the nForce 600 lineup for Intel processors. At the high-end, you have the nForce 680i SLI chipset, which has all of the bells and whistles. Many of these high-end features were cut for the mid-range nForce 650i SLI platform, although it still offered SLI Multi-GPU support, albeit in a somewhat limited manner (only 8 x 8 lanes instead of a full 16 x 16). On the low-end, Nvidia is producing the nForce 650i Ultra, which drops SLI support from the mix, and hasn't been well adopted by motherboard makers and OEM markets. This is possibly due to the fact that the nForce 650i SLI has dropped in price significantly since launch, making it viable even for mid-range desktops who don't specifically need SLI.

However, while most have been satisfied with the tiered structure of Nvidia's nForce 600 series of products, there is a fairly large price gap sitting between the nForce 680i and nForce 650i. A quick scan on Newegg shows 680i boards ranging from $230 - $350, whereas nForce 650i boards are going for anywhere from $115 - $165, roughly half the prices of the 680i. While the nForce 650i has been popular with budget gamers, the 680i is often criticized for being over-priced in comparison to other high-end chipsets.

Today, Nvidia is looking to fill the gap between the 650i SLI and 680i SLI with a new product, the nForce 680i LT SLI. This chipset, which is a trimmed down version of the full-blown 680i SLI, is targeting the $199 price range "sweet spot" to compete against the Intel 975X chipset. This move allows Nvidia to counter Intel's offerings at every major price point. The first board hitting the market will be from eVGA, but it was designed by Nvidia themselves. We've managed to get our hands on a board for an evaluation and will showcase it here for you today. 

Shipping Box - Front

Shipping Box - Back

NVIDIA nForce 680i LT SLI
Features and Specifications
"The Nvidia nForce 680i LT SLI "Designed by Nvidia" motherboard is engineered for the extreme gamer. Featuring award-winning Nvidia nForce 680i SLI performance at a great price, the Nvidia nForce 680i LT includes true dual x16 PCI Express slots with support for Nvidia SLI technology, and SLI-Ready memory with EPP for one-click access to enhanced memory settings. This motherboard delivers best-in-class overclocking capability, allowing extreme gamers to push their CPU and memory components to the next level. Coupled with tools like NV BIOS and Nvidia nTune utility for Microsoft Windows, the Nvidia nForce 680i LT SLI motherboard gives gamers complete control of their system."
  • Intel Core 2 Extreme, Core 2 Quad, Core 2 Duo, Pentium EE, and Pentium Processor Support
  • Nvidia nForce 680i LI SLI Chipset
  • 1333, 1066, 800 MHz Front Side Bus Speeds
  • Dual Channel DDR2 800, 667, 533
  • SLI Ready Memory with EPP x 4 DIMMS, Max 8 GB
  • Nvidia LinkBoost Technology
  • 2 x PCI Express x16 Graphics Card Slots, SLI Ready
  • 2 x PCI Express x1 Slots, 2 x 32-bit PCI Slots
  • 1 x Ultra ATA/133 Port, 1 x Floppy Port
  • 6 x Nvidia Serial ATA-II Ports
  • Supports RAID 0, 1, 0+1, 5, JBOD, eSATA Ready
  • 7.1 Channel Audio, Azalia (HD Audio)
  • 1 x Nvidia Gigabit Ethernet
  • 8 x USB 2.0 Ports, 2 x 1394A Ports
  • Nvidia MediaShield Storage Technology
  • NVidia nTune Performance Applications
  • Nvidia FirstPacket Technology, TCP/IP Acceleration
  • Dual Active Chipset Coolers
  • Standard ATX Form Factor, 12 x 9.6", Green PCB

The board we're looking at is designed by Nvidia, and manufactured by their partners, in this case eVGA. The board shares an identical core design to eVGA's previous nForce 680i platform, but with a few features missing in this incarnation of the nForce 680i LT chipset. Here are the fundamental differences between an nForce 680i SLI board and an nForce 680i SLI LT board.

No Triple PCIe x16 Card Support - Full nForce 680i platforms support dual PCI Express x16 cards along with a third PCI Express x16 slot (with x8 signaling). This slot is designed for dedicated PCI Express physics cards (which have still yet to hit the market) or an additional graphics card or RAID card. As utilization of this slot has been low, Nvidia decided to cut out this feature in order to cut down on costs. Most users will not miss this slot.

No Dual-LAN Support - The nForce 680i LT SLI chipset only supports one native Gigabit Ethernet port, as opposed to two on the 680i SLI. This also means that Nvidia's DualNet technology (which pairs multiple GigE links together) is out of the running on this chipset. The 680i LT SLI only supports a single Gigabit Ethernet port and Nvidia's FirstPacket priority optimization features. We should note that third party motherboard manufacturers could indeed provide dual-NICs, although they would have to rely on third party components connected to the PCIe/PCI bus, not native to the chipset. The majority of users only use one Gigabit Ethernet port, so again, this feature won't be missed by many.

No DDR2-1200 Support - This chipset only "officially" supports memory speeds up to 800 MHz, whereas the full 680i SLI chipset supported speeds up to 1200 MHz officially. Keep in mind, while this chipset only "officially" allows DDR speeds up to 800 MHz, the BIOS of this motherboard is fully equipped to run at much higher speeds, which we verified in testing.

No Board Level "Bling" - eVGA's full 680i SLI board featured a black PCB and diagnostic LED indicators, whereas this 680i board features no LED indicators and a standard green PCB.

Active Cooling - In our opinion, this may be the biggest notable change between the 680i SLI and the 680i LT SLI boards from eVGA. In order to cut down costs, eVGA/Nvidia removed the passive heatpipe based cooling of the two chipset components, opting instead for two small chipset coolers, each with fans. Now, the original 680i SLI's heatpipe cooler ran fairly hot so using the (optional) fan was more or less a requirement for power users. However, this board takes this efficient cooling system out of the mix, going for a more traditional route which is a noisier solution overall.

It's also important to note that all 680i LT SLI boards won't have active cooling - it's not a requirement, but eVGA is going this route. It's very possible that other board manufacturers will use passive heatpipe cooling solutions for their boards as well.

Design and Features

Design and Features

Now that we've seen what's missing from the 680i LT SLI chipset in comparison to the full 680i SLI, let's see what this board has going for it. As mentioned before, the board is built upon a basic green PCB using a standard ATX form factor, and has been designed meticulously with the gamer/enthusiast in mind. The design of this board, at its core, is identical to eVGA's full 680i board, although the features listed on the previous page are simply not installed on the PCB. You can still see the solder points for the dedicated second NIC, third PCIe slot, and diagnostic LED code display on this board. 



The board features a Socket-775 interface, fully capable of handling all nature of dual and quad-core Intel processors in this particular form factor. The board also supports the soon-to-be-released 1333 MHz FSB based Core 2 processors, so you've got some measure of future-proofing built-in with this board. The CPU socket is left mostly clear around its edges, and most large Socket-775 coolers will have no problem fitting on this board. The socket is surrounded by heatsinks on nearly all sides - to the top and left by VRM cooling heatsinks and to the bottom by the nForce 680i LT Northbridge cooler.

The nForce 680i LT SLI's memory controller supports up to 8GB of DDR2-800 memory over 4 x DDR2 DIMM sockets. The DIMM sockets are close to four of the motherboard's Serial ATA ports, so this area can get quite crowded if you're using these SATA ports along with a full set of memory modules. As we've mentioned before, the board is capable of overclocking well past DDR2-800 speeds (we were able to run up to 1155 MHz in testing), and the board also features memory speed alteration independent of the FSB, meaning you can push the memory speed as far as you like without touching the processor's front side bus speeds.

The actual nForce 680i LT SLI chipset is comprised of two components, the SPP which is cooled by a hefty chipset cooler with a 50mm cooling fan, along with the MCP which sits between the PCI Express slots and is cooled by a smaller, shorter cooler with a low-speed fan. 

nForce 680i SPP

nForce 680i MCP

The MCP cooler is a very low-speed unit, and is nearly inaudible when running. However, the larger SPP chipset cooler can be quite loud when running at full speed. This cooler was the loudest component of our testbed setup. Nvidia does let you alter the SPP chipset cooler's speed down to 50% of its full speed level, but even at this level, the cooler is still audible in most environments. Enthusiasts who want a lower-noise environment should note that this cooler can be removed (of course, voiding your warranty) and replaced with a third party chipset cooler, as the standard chipset cooler mounting pegs are indeed in place. We would have preferred that eVGA/Nvidia come up with a lower-noise solution to chipset cooling, but given that this product is targeting the cost conscious consumer, it's not surprising to see deluxe chipset cooling go.

Design Continued

Design Continued

One of the most impressive features, considering this is technically a mid-range priced motherboard, is the 680i LT SLI's  two full PCI Express x16 slots for true 16x16 SLI support. Previously, 16x16 SLI was kept for Nvidia's high-end products, but this product shows that this feature will finally be drifting down to the mass market level. While mosts tests show that 16 x 16 SLI shows only a slight performance boost over an 8 x 8 SLI configuration in most scenarios, it's always a positive to know that your high-end graphics cards are running at their full, intended speeds without any potential bottlenecks. This secondary PCI Express x16 slot can also be used for other PCI Express devices if not needed for graphics. These slots are also useful for those looking to setup high-speed multi-monitor configurations.


Dual PCI Express x16 Slots (16 x 16 SLI Ready)

In addition to the two PCI Express x16 slots, this motherboard is equipped with two PCI Express x1 slots and two 32-bit PCI slots. There is a slot left "open" in the middle, which is where the third PCI Express x16 slot would go on a full 680i SLI board.

The board features six Serial ATA-II/300 ports on the right side of the board, four of which are sandwiched between the memory banks and IDE slot, two more of which sit off edge of the PCB, and are better positioned for "clean-cabling" environments. All of these ports support RAID functionality through Nvidia's NVRAID MCP, including RAID 0, 1, 0+1, and 5. The board also supports one standard Ultra ATA/133 and a floppy port. This board requires a 24-pin primary ATX power connector and an 8-pin secondary ATX connector. The connectors are positioned well, so as to not obstruct case airflow and allow for clean cable routing. 

eVGA nForce 680i LT SLI I/O Panel

As for the I/O panel, the board is quite feature packed considering its price point. A quick glance shows (left to right) PS/2 mouse and keyboard ports, a single 6-pin Firewire 400 port, two USB 2.0 ports, an optical S/PDIF digital audio port, 8-channel analog audio ports, a single Gigabit Ethernet port and two more USB 2.0 ports. The motherboard also has pins to connect another Firewire port along with four more USB 2.0 ports (for a total of eight USB 2.0 ports and two Firewire 400 ports).

Onboard audio functionality is handled by a Realtek ALC885 high-definition (HD) / Azalia audio CODEC. This audio chip supports 7.1/8-channel audio along with up to 24-bit S/PDIF digital output, along with EAX and DirectSound support. For heavy gamers, we would still opt for a dedicated audio card, although the onboard audio should certainly suffice for the vast majority of gamers out there. Onboard LAN is connected through a Marvell PCI Express PHY which connects to the Nvidia MCP. 

Realtek HD Audio CODEC and Marvell Gigabit Ethernet PHY

As for bundled extras, eVGA does things right with a clean, simple, but functional array of cables. eVGA includes black rounded IDE and floppy cables, along with six companion black Serial ATA cables and Serial ATA power adapters. Also bundled are rear panel adapters for Serial, USB, and Firewire, which allow you to route these pin-level connectors to the back of your case if you're not using them to connect to the front of your chassis. eVGA also includes an SLI bridge, I/O shield, driver disks, and a quick install manual. Nothing more, nothing less - just what we need to get this board up and running.

BIOS and Overclocking

BIOS and Overclocking

eVGA's nForce 680i LT SLI board comes equipped with an Award BIOS which is more or less identical to the BIOS featured on their full 680i SLI board. While the particular BIOS we used was still technically a beta revision, we found the board to be extremely stable, even when heavily overclocked.

While many boards note the ability for to revert to "safe" settings when overclocked too far (instead of just hanging at the startup screen), most boards typically don't handle this feature well. We found that the eVGA board was excellent in this regard, simply dropping us back to the BIOS menu if we tried to overclock too much. It's simple and safe to find your maximum overclock with this board, without having to reset the CMOS and swap jumpers. 

FSB / Memory Clock Alteration

Memory Timing Alteration

While the board technically only supports FSB speeds up to 1333 MHz and DDR speeds up to 800 MHz, we found that our test board was able to go much higher. On the front side bus level, we were able to take our 1066 MHz Core 2 Duo E6600 processor up to 1800 MHz front side bus speed with very slight voltage boosts. On the DDR2 side, we were able to bring modules up to 1185 MHz, just short of the 1200 MHz offered by full 680i SLI boards. The BIOS allows for much higher levels, too, if your components can handle such levels. Also offered is a wide range of memory tweaking functions, along with voltage alteration for vCore, FSB, memory, and SPP. You can also monitor fans and adjust fan speeds (depending on load, or hard-set their speeds) in the BIOS as well. While a board like the Asus Striker Extreme will give you more tweaking options, we're happy with the options which this board provides, which we feel will be enough to satisfy the needs of all but the most hardcore overclockers.

We've run a set of benchmarks at stock speeds along with overclocked speeds, so you can see what kind of performance one can get with a simple air-clocked overclocked system. For these tests, we took our Core 2 Duo E6600 (2.4 GHz) and clocked it up to 3.15 GHz (1800 MHz) FSB, and boosted our memory clock from 800 MHz up to 1066 MHz at CAS 4-4-4-12 timings. 

Voltage Alteration

Voltage and Thermal Monitoring

Test Systems and Sandra Performance

Test System Details
Specifications and Revisions
  • Intel Core 2 Duo E6600 (2.4 GHz) Processor
  • 2 x Corsair XMS DDR2-800 Memory (2 x 1 GB, CAS 4-4-4-12)
  • 1 x Nvidia GeForce 7900 GT 256 MB (Nvidia 93.71 Driver)
  • 1 x Maxtor DiamondMax 10 Serial ATA Hard Disk
  • 1 x Plextor PX-755SA DVD+/-RW Drive
  • 1 x Corsair HX620W 620W Power Supply
  • Windows XP Professional SP2 (32-bit)


  • eVGA nForce 680i LT Chipset (2.053.72 BIOS)
  • Asus P5N-E SLI Nvidia nForce 650i SLI Chipset (0304 BIOS)
  • Asus Striker Extreme Nvidia nForce 680i SLI Chipset (701 BIOS)
  • Asus P5NSLI Nvidia nForce 570 SLI Chipset (0903 BIOS)
  • Asus P5W DH Deluxe Intel 975X Chipset (1707 BIOS)
  • Asus P5B Deluxe Intel P965 Chipset (0804 BIOS)
Synthetic CPU and Memory Benchmarks
SiSoft Sandra XI

Our synthetic tests show the nForce 680i LT right in line with other high-end Socket-775 platforms in terms of raw processor and memory performance. While CPU performance is more or less identical to other high-end boards (as it should be, when all processors are clocked at the same level), we see some interesting memory issues. The nForce 680i LT shows a slight dip in bandwidth and slightly higher latencies compared to the nForce 680i (Striker Extreme).

3DMark and PCMark Performance

Synthetic Futuremark Benchmarks
3DMark05 and PCMark05

Our synthetic system-wide benchmarks show the 680i LT right in line with the more expensive 680i SLI boards, as well as other high-end Socket-775 boards. The 680i LT shows a (very) slim advantage in 3DMark, while dropping a tad in PCMark. However, the numbers are so close that there is no noticeable performance differences between the majority of these platforms when they are all running with the same speed processor and memory.

Rendering and Encoding Performance


Graphics Creation and Encoding Benchmarks
Cinebench 9.5 and DivX Converter

Professional / workstation-class application users should have no problems with the nForce 680i LT, as performance levels are on par with all other high-end boards. These CPU-specific tests show the 680i LT performing just as we would have expected.

Gaming Performance

Gaming Benchmarks
Half Life 2, Prey, and FEAR

Interestingly, the 680i LT shows a bit lower performance in a gaming environment than we expected. In all three of our gaming benchmarks, the 680i LT is out performed by the 680i SLI by a small margin. As gaming environments are heavy on memory usage, our 680i LT's lower memory performance and higher latencies are the likely culprit here. In any case, the performance drop certainly isn't large, and our numbers when overclocked are still quite good. These slight differences may be eliminated as the BIOS is tuned for this board over time.

Storage Performance

Storage Benchmarks
HDTach 3.0 Hard Drive Benchmark

The nForce 680i LT's integrated Serial ATA storage system is top notch, delivering excellent burst transfer rates (the highest of our tests), along with sustained transfer rates on par with other high-end solution. Interestingly, the 680i LT registered a bit more CPU utilization (%) compared to other chipsets, although not enough to make any major difference in overall system performance.

Our Conclusion

Our Conclusion

Nvidia's nForce 680i LT SLI chipset is a terrific high-end platform with a reasonable price-tag, plain and simple. As Nvidia already produces two sought after chipset products at the high and mid-levels of the market (the 680i SLI and 650i SLI), it didn't even occur many folks that a trimmed down 680i SLI could fit in the middle. However, the 680i LT SLI manages to slip in-between these two products nicely. 

The 680i LT SLI isn't revolutionary - everything we're seeing here today are things which we've already seen with the full-fledged 680i SLI chipset. However, we're happy to see Nvidia bringing full speed PCI Express 16 x 16 SLI support down to a more reasonable price point. nForce 680i LT boards deliver all of the high-end gaming performance of the 680i SLI, but at a much lower price, which we can only see as a good thing.

As for the components omitted in order to hit the 680i LT's lower price point, Nvidia made most of the right calls. Removing the third PCI Express x16 slot was right, as this slot is largely un-used at this point in time. In addition, Dual GigE support and a diagnostic POST code error reported (while useful), aren't frequently used items. DDR-1200 support was tough to hit on full-fledged 680i SLI boards (partially due to DDR2-1200 memory modules still being somewhat immature), so "removing" this feature won't cause a problem for most users. As our overclocking tests show, this chipset can easily handle DDR2-1066 and higher speeds without issue, so we really don't even consider this feature missing from the LT anyway.

The one item that didn't set well with us was the active chipset cooler. Dual chipset fans are something the motherboard industry had moved away from, as noise now plays a major factor in purchasing decisions. The board is probably too loud for those seeking a quiet PC, although we will say that most gamers won't mind the additional noise due to the board's lowered price point. Perhaps third party manufacturers like Asus and Gigabyte will produce passively cooled 680i LT solutions in the future.

As a whole, we're very much impressed with the 680i LT platform, and we think Nvidia will sell them in bunches. However, the price point and feature set may cannibalize sales of both the 680i and 650i SLI chipsets in the process. Certainly Nvidia is aware of this and feels releasing the 680i LT SLI is the right direction to go. The platform simply has a great mix of features, overclockability, and an attractive price point.

  • Full 16 x 16 SLI Support
  • Highly Overclockable
  • Attractive Price Point
  • Dual Active Chipset Coolers
  • Single Gigabit Ethernet Port

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